2 * Based on arch/arm/mm/init.c
4 * Copyright (C) 1995-2005 Russell King
5 * Copyright (C) 2012 ARM Ltd.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <linux/kernel.h>
21 #include <linux/export.h>
22 #include <linux/errno.h>
23 #include <linux/swap.h>
24 #include <linux/init.h>
25 #include <linux/bootmem.h>
26 #include <linux/mman.h>
27 #include <linux/nodemask.h>
28 #include <linux/initrd.h>
29 #include <linux/gfp.h>
30 #include <linux/memblock.h>
31 #include <linux/sort.h>
32 #include <linux/of_fdt.h>
33 #include <linux/dma-mapping.h>
34 #include <linux/dma-contiguous.h>
35 #include <linux/efi.h>
36 #include <linux/swiotlb.h>
39 #include <asm/fixmap.h>
40 #include <asm/kasan.h>
41 #include <asm/kernel-pgtable.h>
42 #include <asm/memory.h>
43 #include <asm/sections.h>
44 #include <asm/setup.h>
45 #include <asm/sizes.h>
47 #include <asm/alternative.h>
52 * We need to be able to catch inadvertent references to memstart_addr
53 * that occur (potentially in generic code) before arm64_memblock_init()
54 * executes, which assigns it its actual value. So use a default value
55 * that cannot be mistaken for a real physical address.
57 phys_addr_t memstart_addr __read_mostly = ~0ULL;
58 phys_addr_t arm64_dma_phys_limit __read_mostly;
60 #ifdef CONFIG_BLK_DEV_INITRD
61 static int __init early_initrd(char *p)
63 unsigned long start, size;
66 start = memparse(p, &endp);
68 size = memparse(endp + 1, NULL);
71 initrd_end = start + size;
75 early_param("initrd", early_initrd);
79 * Return the maximum physical address for ZONE_DMA (DMA_BIT_MASK(32)). It
80 * currently assumes that for memory starting above 4G, 32-bit devices will
83 static phys_addr_t __init max_zone_dma_phys(void)
85 phys_addr_t offset = memblock_start_of_DRAM() & GENMASK_ULL(63, 32);
86 return min(offset + (1ULL << 32), memblock_end_of_DRAM());
89 static void __init zone_sizes_init(unsigned long min, unsigned long max)
91 struct memblock_region *reg;
92 unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
93 unsigned long max_dma = min;
95 memset(zone_size, 0, sizeof(zone_size));
97 /* 4GB maximum for 32-bit only capable devices */
98 #ifdef CONFIG_ZONE_DMA
99 max_dma = PFN_DOWN(arm64_dma_phys_limit);
100 zone_size[ZONE_DMA] = max_dma - min;
102 zone_size[ZONE_NORMAL] = max - max_dma;
104 memcpy(zhole_size, zone_size, sizeof(zhole_size));
106 for_each_memblock(memory, reg) {
107 unsigned long start = memblock_region_memory_base_pfn(reg);
108 unsigned long end = memblock_region_memory_end_pfn(reg);
113 #ifdef CONFIG_ZONE_DMA
114 if (start < max_dma) {
115 unsigned long dma_end = min(end, max_dma);
116 zhole_size[ZONE_DMA] -= dma_end - start;
120 unsigned long normal_end = min(end, max);
121 unsigned long normal_start = max(start, max_dma);
122 zhole_size[ZONE_NORMAL] -= normal_end - normal_start;
126 free_area_init_node(0, zone_size, min, zhole_size);
129 #ifdef CONFIG_HAVE_ARCH_PFN_VALID
130 int pfn_valid(unsigned long pfn)
132 return memblock_is_map_memory(pfn << PAGE_SHIFT);
134 EXPORT_SYMBOL(pfn_valid);
137 #ifndef CONFIG_SPARSEMEM
138 static void __init arm64_memory_present(void)
142 static void __init arm64_memory_present(void)
144 struct memblock_region *reg;
146 for_each_memblock(memory, reg)
147 memory_present(0, memblock_region_memory_base_pfn(reg),
148 memblock_region_memory_end_pfn(reg));
152 static phys_addr_t memory_limit = (phys_addr_t)ULLONG_MAX;
155 * Limit the memory size that was specified via FDT.
157 static int __init early_mem(char *p)
162 memory_limit = memparse(p, &p) & PAGE_MASK;
163 pr_notice("Memory limited to %lldMB\n", memory_limit >> 20);
167 early_param("mem", early_mem);
169 void __init arm64_memblock_init(void)
171 const s64 linear_region_size = -(s64)PAGE_OFFSET;
174 * Select a suitable value for the base of physical memory.
176 memstart_addr = round_down(memblock_start_of_DRAM(),
177 ARM64_MEMSTART_ALIGN);
180 * Remove the memory that we will not be able to cover with the
181 * linear mapping. Take care not to clip the kernel which may be
184 memblock_remove(max(memstart_addr + linear_region_size, __pa(_end)),
186 if (memblock_end_of_DRAM() > linear_region_size)
187 memblock_remove(0, memblock_end_of_DRAM() - linear_region_size);
190 * Apply the memory limit if it was set. Since the kernel may be loaded
191 * high up in memory, add back the kernel region that must be accessible
192 * via the linear mapping.
194 if (memory_limit != (phys_addr_t)ULLONG_MAX) {
195 memblock_enforce_memory_limit(memory_limit);
196 memblock_add(__pa(_text), (u64)(_end - _text));
199 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE)) {
200 extern u16 memstart_offset_seed;
201 u64 range = linear_region_size -
202 (memblock_end_of_DRAM() - memblock_start_of_DRAM());
205 * If the size of the linear region exceeds, by a sufficient
206 * margin, the size of the region that the available physical
207 * memory spans, randomize the linear region as well.
209 if (memstart_offset_seed > 0 && range >= ARM64_MEMSTART_ALIGN) {
210 range = range / ARM64_MEMSTART_ALIGN + 1;
211 memstart_addr -= ARM64_MEMSTART_ALIGN *
212 ((range * memstart_offset_seed) >> 16);
217 * Register the kernel text, kernel data, initrd, and initial
218 * pagetables with memblock.
220 memblock_reserve(__pa(_text), _end - _text);
221 #ifdef CONFIG_BLK_DEV_INITRD
223 memblock_reserve(initrd_start, initrd_end - initrd_start);
225 /* the generic initrd code expects virtual addresses */
226 initrd_start = __phys_to_virt(initrd_start);
227 initrd_end = __phys_to_virt(initrd_end);
231 early_init_fdt_scan_reserved_mem();
233 /* 4GB maximum for 32-bit only capable devices */
234 if (IS_ENABLED(CONFIG_ZONE_DMA))
235 arm64_dma_phys_limit = max_zone_dma_phys();
237 arm64_dma_phys_limit = PHYS_MASK + 1;
238 dma_contiguous_reserve(arm64_dma_phys_limit);
240 memblock_allow_resize();
244 void __init bootmem_init(void)
246 unsigned long min, max;
248 min = PFN_UP(memblock_start_of_DRAM());
249 max = PFN_DOWN(memblock_end_of_DRAM());
251 early_memtest(min << PAGE_SHIFT, max << PAGE_SHIFT);
254 * Sparsemem tries to allocate bootmem in memory_present(), so must be
255 * done after the fixed reservations.
257 arm64_memory_present();
260 zone_sizes_init(min, max);
262 high_memory = __va((max << PAGE_SHIFT) - 1) + 1;
263 max_pfn = max_low_pfn = max;
266 #ifndef CONFIG_SPARSEMEM_VMEMMAP
267 static inline void free_memmap(unsigned long start_pfn, unsigned long end_pfn)
269 struct page *start_pg, *end_pg;
270 unsigned long pg, pgend;
273 * Convert start_pfn/end_pfn to a struct page pointer.
275 start_pg = pfn_to_page(start_pfn - 1) + 1;
276 end_pg = pfn_to_page(end_pfn - 1) + 1;
279 * Convert to physical addresses, and round start upwards and end
282 pg = (unsigned long)PAGE_ALIGN(__pa(start_pg));
283 pgend = (unsigned long)__pa(end_pg) & PAGE_MASK;
286 * If there are free pages between these, free the section of the
290 free_bootmem(pg, pgend - pg);
294 * The mem_map array can get very big. Free the unused area of the memory map.
296 static void __init free_unused_memmap(void)
298 unsigned long start, prev_end = 0;
299 struct memblock_region *reg;
301 for_each_memblock(memory, reg) {
302 start = __phys_to_pfn(reg->base);
304 #ifdef CONFIG_SPARSEMEM
306 * Take care not to free memmap entries that don't exist due
307 * to SPARSEMEM sections which aren't present.
309 start = min(start, ALIGN(prev_end, PAGES_PER_SECTION));
312 * If we had a previous bank, and there is a space between the
313 * current bank and the previous, free it.
315 if (prev_end && prev_end < start)
316 free_memmap(prev_end, start);
319 * Align up here since the VM subsystem insists that the
320 * memmap entries are valid from the bank end aligned to
321 * MAX_ORDER_NR_PAGES.
323 prev_end = ALIGN(__phys_to_pfn(reg->base + reg->size),
327 #ifdef CONFIG_SPARSEMEM
328 if (!IS_ALIGNED(prev_end, PAGES_PER_SECTION))
329 free_memmap(prev_end, ALIGN(prev_end, PAGES_PER_SECTION));
332 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
335 * mem_init() marks the free areas in the mem_map and tells us how much memory
336 * is free. This is done after various parts of the system have claimed their
337 * memory after the kernel image.
339 void __init mem_init(void)
343 set_max_mapnr(pfn_to_page(max_pfn) - mem_map);
345 #ifndef CONFIG_SPARSEMEM_VMEMMAP
346 free_unused_memmap();
348 /* this will put all unused low memory onto the freelists */
351 mem_init_print_info(NULL);
353 #define MLK(b, t) b, t, ((t) - (b)) >> 10
354 #define MLM(b, t) b, t, ((t) - (b)) >> 20
355 #define MLG(b, t) b, t, ((t) - (b)) >> 30
356 #define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
358 pr_notice("Virtual kernel memory layout:\n"
360 " kasan : 0x%16lx - 0x%16lx (%6ld GB)\n"
362 " modules : 0x%16lx - 0x%16lx (%6ld MB)\n"
363 " vmalloc : 0x%16lx - 0x%16lx (%6ld GB)\n"
364 " .init : 0x%p" " - 0x%p" " (%6ld KB)\n"
365 " .text : 0x%p" " - 0x%p" " (%6ld KB)\n"
366 " .data : 0x%p" " - 0x%p" " (%6ld KB)\n"
367 #ifdef CONFIG_SPARSEMEM_VMEMMAP
368 " vmemmap : 0x%16lx - 0x%16lx (%6ld GB maximum)\n"
369 " 0x%16lx - 0x%16lx (%6ld MB actual)\n"
371 " fixed : 0x%16lx - 0x%16lx (%6ld KB)\n"
372 " PCI I/O : 0x%16lx - 0x%16lx (%6ld MB)\n"
373 " memory : 0x%16lx - 0x%16lx (%6ld MB)\n",
375 MLG(KASAN_SHADOW_START, KASAN_SHADOW_END),
377 MLM(MODULES_VADDR, MODULES_END),
378 MLG(VMALLOC_START, VMALLOC_END),
379 MLK_ROUNDUP(__init_begin, __init_end),
380 MLK_ROUNDUP(_text, _etext),
381 MLK_ROUNDUP(_sdata, _edata),
382 #ifdef CONFIG_SPARSEMEM_VMEMMAP
383 MLG((unsigned long)vmemmap,
384 (unsigned long)vmemmap + VMEMMAP_SIZE),
385 MLM((unsigned long)phys_to_page(memblock_start_of_DRAM()),
386 (unsigned long)virt_to_page(high_memory)),
388 MLK(FIXADDR_START, FIXADDR_TOP),
389 MLM(PCI_IO_START, PCI_IO_END),
390 MLM(__phys_to_virt(memblock_start_of_DRAM()),
391 (unsigned long)high_memory));
398 * Check boundaries twice: Some fundamental inconsistencies can be
399 * detected at build time already.
402 BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64);
404 BUILD_BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
405 BUG_ON(TASK_SIZE_64 > MODULES_VADDR);
407 if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) {
408 extern int sysctl_overcommit_memory;
410 * On a machine this small we won't get anywhere without
411 * overcommit, so turn it on by default.
413 sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
417 void free_initmem(void)
419 free_initmem_default(0);
423 #ifdef CONFIG_BLK_DEV_INITRD
425 static int keep_initrd __initdata;
427 void __init free_initrd_mem(unsigned long start, unsigned long end)
430 free_reserved_area((void *)start, (void *)end, 0, "initrd");
433 static int __init keepinitrd_setup(char *__unused)
439 __setup("keepinitrd", keepinitrd_setup);
443 * Dump out memory limit information on panic.
445 static int dump_mem_limit(struct notifier_block *self, unsigned long v, void *p)
447 if (memory_limit != (phys_addr_t)ULLONG_MAX) {
448 pr_emerg("Memory Limit: %llu MB\n", memory_limit >> 20);
450 pr_emerg("Memory Limit: none\n");
455 static struct notifier_block mem_limit_notifier = {
456 .notifier_call = dump_mem_limit,
459 static int __init register_mem_limit_dumper(void)
461 atomic_notifier_chain_register(&panic_notifier_list,
462 &mem_limit_notifier);
465 __initcall(register_mem_limit_dumper);